From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933955AbcAKQe6 (ORCPT ); Mon, 11 Jan 2016 11:34:58 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:46788 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760561AbcAKQe4 (ORCPT ); Mon, 11 Jan 2016 11:34:56 -0500 Message-Id: <20160111163229.115404507@infradead.org> User-Agent: quilt/0.61-1 Date: Mon, 11 Jan 2016 17:25:05 +0100 From: Peter Zijlstra To: mingo@kernel.org, alexander.shishkin@linux.intel.com, eranian@google.com Cc: linux-kernel@vger.kernel.org, vince@deater.net, dvyukov@google.com, andi@firstfloor.org, jolsa@redhat.com, peterz@infradead.org Subject: [RFC][PATCH 07/12] perf: Simplify/fix perf_event_enable() event scheduling References: <20160111162458.427203780@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=peterz-perf-fixes-8.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Like enable_on_exec, perf_event_enable() event scheduling has problems respecting the context hierarchy when trying to schedule events (for example, it will try and add a pinned event without first removing existing flexible events). So simplify it by using the new ctx_resched() call which will DTRT. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 31 +++++-------------------------- 1 file changed, 5 insertions(+), 26 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2188,7 +2188,7 @@ static int __perf_event_enable(void *inf struct perf_event_context *ctx = event->ctx; struct perf_event *leader = event->group_leader; struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); - int err; + struct perf_event_context *task_ctx = cpuctx->task_ctx; /* * There's a time window between 'ctx->is_active' check @@ -2202,7 +2202,8 @@ static int __perf_event_enable(void *inf if (!ctx->is_active) return -EINVAL; - raw_spin_lock(&ctx->lock); + perf_ctx_lock(cpuctx, task_ctx); + WARN_ON_ONCE(&cpuctx->ctx != ctx && task_ctx != ctx); update_context_time(ctx); if (event->state >= PERF_EVENT_STATE_INACTIVE) @@ -2228,32 +2229,10 @@ static int __perf_event_enable(void *inf if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) goto unlock; - if (!group_can_go_on(event, cpuctx, 1)) { - err = -EEXIST; - } else { - if (event == leader) - err = group_sched_in(event, cpuctx, ctx); - else - err = event_sched_in(event, cpuctx, ctx); - } - - if (err) { - /* - * If this event can't go on and it's part of a - * group, then the whole group has to come off. - */ - if (leader != event) { - group_sched_out(leader, cpuctx, ctx); - perf_mux_hrtimer_restart(cpuctx); - } - if (leader->attr.pinned) { - update_group_times(leader); - leader->state = PERF_EVENT_STATE_ERROR; - } - } + ctx_resched(cpuctx, task_ctx); unlock: - raw_spin_unlock(&ctx->lock); + perf_ctx_unlock(cpuctx, task_ctx); return 0; }